The effect of embryo catheter loading technique on the live birth rate

Omidi, Marjan,Halvaei, Iman,Mangoli, Esmat,Khalili, Mohammad Ali,Razi, Mohammad Hossein The Korean Society for Reproductive Medicine 2015 Clinical and Experimental Reproductive Medicine Vol.42 No.4

Objective: Embryo loading (EL) is a major step in embryo transfer (ET) and affect on the success of in vitro fertilization (IVF). This study aimed to compare the effect of two different EL techniques on the rates of pregnancy and delivery in IVF/ET cycles. Methods: 207 fresh ET and 194 Frozen-thawed ET (FET) cycles were included in this retrospective study. Two groups (A and B) were defined based on the EL technique used. In group A, the entire catheter was flushed with Ham's F-10 medium. The embryos were then drawn into the catheter using one air bracket. In group B, $70{\mu}L$ of air was aspirated into the syringe and the catheter was flushed using Ham's F10 medium. The medium, air, embryos, air, and finally another layer of medium were then sequentially drawn into the catheter. The main outcome measures were the pregnancy and delivery rates. Results: The groups did not differ with respect to the etiology of infertility, the source of spermatozoa, the quality of the embryos, the type of EL catheter, and the ease of transfer. The pregnancy rate was similar between two groups. In fresh ET cycles, a higher delivery rate was observed in group B than it group A (78.1% vs. 60%, p=0.1). In FET cycles, the rate of delivery was significantly higher in group B than in group A to a nonsignificant extent (88.9% vs. 58.8%, p=0.06). Conclusion: EL techniques did not have a significant impact on the delivery rate in either fresh or FET cycles.

Investigating on performance parameters and flow field of centrifugal compressor based on the splitter blade leading edge's location effect

Mohammad Omidi,Yan Liu,Soheil Mohtaram,Shuai Li 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.8

Impeller design in turbomachines is one of the most challenging issues in these machines' systems, which still plays a significant role in their efficiency and performance. This article considers different designs for splitter blades. Therefore, the CFD methods modify the position of the splitter blades leading edge at the hub and shroud. This modification shall lead to a different splitter blade profile from the main blades. Then, the effects of splitter blades are discussed, and the performance parameters have also been studied to improve this method's implementation. The results revealed that the compressor's efficiency was improved by approximately 1.5 % in one specific case. This finding proves that the previous design methods were not the optimum ones for compressors and how to increase the compressor's efficiency by CFD methods and by changing the splitter blades' location.

Application of photoelectro-fenton process modified with porous cathode electrode in removing resistant organic compounds from aquatic solutions: modeling, toxicity and kinetics

Reza Ali Fallahzadeh,Mohammad Hassan Ehrampoush,Mohsen Nabi Meybodi,Mohammad Taghi Ghaneian,Arash Dalvand,Fariborz Omidi,Mohammad Hossein Salmani,Hossien Fallahzadeh,Amir Hossein Mahvi 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.6

The presence of antibiotics in the environment as persistent micropollutants, due to their widespread consumption, has increased the concerns about the harmful effects of these compounds on human and animal health. Advanced oxidation processes are one of the most effective methods to remove these types of organic pollutants. In this study, amoxicillin (AMX) removal in a modified photoelectro-Fenton (PEF) reactor in which porous stainless steel was used as a cathode electrode, and the ability of air injection into its center to produce H2O2 was investigated. A graphite anode electrode equipped with iron rings was used to increase the electrochemical reaction surface and produce iron ions. The effect of current density, time, and electrolyte concentration on AMX removal efficiency was evaluated by Box-Behnken design method. Subsequently, the effect of AMX concentration variable and pH on removal efficiency was investigated. Finally, the chemical oxygen demand (COD) removal efficiency, toxicity, and effluent activity from the PEF reactor were investigated. The results showed that the modified photoelectro-Fenton process could have efficiency of 99% to remove AMX, in 20min using current density of 36 mA/cm2 and 16mM/L electrolyte concentration. Reducing pH and AMX concentration increased the removal efficiency. The PEF process can completely remove the COD in 58 min. Also, toxicity studies indicated an effective reduction in the effluent. This modified reactor improves the efficiency of the PEF process, which, in addition to the 99% removal of AMX, provides a proper function for COD removal, reducing the toxicity properties of the effluent.

Risk Assessment of Exposure to Silica Dust in Building Demolition Sites

Mohammad Normohammadi,Hossein Kakooei,Leila Omidi,Saeed Yari,Rasul Alimi 한국산업안전보건공단 산업안전보건연구원 2016 Safety and health at work Vol.7 No.3

Background: Building demolition can lead to emission of dust into the environment. Exposure to silica dust may be considered as an important hazard in these sites. The objectives of this research were to determine the amount of workers’ exposure to crystalline silica dust and assess the relative risk of silicosis and the excess lifetime risk of mortality from lung cancer in demolition workers. Methods: Four sites in the Tehran megacity region were selected. Silica dust was collected using the National Institute for Occupational Safety and Health method 7601 and determined spectrophotometrically. The Mannetje et al and Rice et al models were chosen to examine the rate of silicosis-related mortality and the excess lifetime risk of mortality from lung cancer, respectively. Results: The amount of demolition workers’ exposure was in the range of 0.085-0.185 mg/m3. The range of relative risk of silicosis related mortality was increased from 1 in the workers with the lowest exposure level to 22.64/1,000 in the employees with high exposure level. The range of the excess lifetime risk of mortality from lung cancer was in the range of 32-60/1,000 exposed workers. Conclusion: Geometric and arithmetic mean of exposure was higher than threshold limit value for silica dust in all demolition sites. The risk of silicosis mortality for many demolition workers was higher than 1/ 1,000 (unacceptable level of risk). Estimating the lifetime lung cancer mortality showed a higher risk of mortality from lung cancer in building demolition workers.

Risk Assessment of Exposure to Silica Dust in Building Demolition Sites

Normohammadi, Mohammad,Kakooei, Hossein,Omidi, Leila,Yari, Saeed,Alimi, Rasul Occupational Safety and Health Research Institute 2016 Safety and health at work Vol.7 No.3

Background: Building demolition can lead to emission of dust into the environment. Exposure to silica dust may be considered as an important hazard in these sites. The objectives of this research were to determine the amount of workers' exposure to crystalline silica dust and assess the relative risk of silicosis and the excess lifetime risk of mortality from lung cancer in demolition workers. Methods: Four sites in the Tehran megacity region were selected. Silica dust was collected using the National Institute for Occupational Safety and Health method 7601 and determined spectrophotometrically. The Mannetje et al and Rice et al models were chosen to examine the rate of silicosis-related mortality and the excess lifetime risk of mortality from lung cancer, respectively. Results: The amount of demolition workers' exposure was in the range of $0.085-0.185mg/m^3$. The range of relative risk of silicosis related mortality was increased from 1 in the workers with the lowest exposure level to 22.64/1,000 in the employees with high exposure level. The range of the excess lifetime risk of mortality from lung cancer was in the range of 32-60/1,000 exposed workers. Conclusion: Geometric and arithmetic mean of exposure was higher than threshold limit value for silica dust in all demolition sites. The risk of silicosis mortality for many demolition workers was higher than 1/1,000 (unacceptable level of risk). Estimating the lifetime lung cancer mortality showed a higher risk of mortality from lung cancer in building demolition workers.

Comparison of Functional Outcomes following Surgical Decompression and Posterolateral Instrumented Fusion in Single Level Low Grade Lumbar Degenerative versus Isthmic Spondylolisthesis

Farzad Omidi-Kashani,Ebrahim Ghayem Hasankhani,Mohammad Dawood Rahimi,Reza Khanzadeh 대한정형외과학회 2014 Clinics in Orthopedic Surgery Vol.6 No.2

Background: The two most common types of surgically treated lumbar spondylolisthesis in adults include the degenerative and isthmic types. The aim of this study was to compare the functional outcomes of surgical decompression and posterolateral instrumented fusion in patients with lumbar degenerative and isthmic spondylolisthesis. Methods: In this retrospective study, we reviewed the clinical outcomes in surgically treated patients with single level, low grade lumbar degenerative, and isthmic spondylolisthesis (groups A and B, respectively) from August 2007 to April 2011. We tried to compare paired settings with similar initial conditions. Group A included 52 patients with a mean age of 49.2 ± 6.1 years, and group B included 52 patients with a mean age of 47.3 ± 7.4 years. Minimum follow-up was 24 months. The surgical procedure comprised neural decompression and posterolateral instrumented fusion. Pain and disability were assessed by a visual analog scale (VAS) and the Oswestry Disability Index (ODI), respectively. The Wilcoxon and Mann-Whitney U-tests were used to compare indices. Results: The most common sites for degenerative and isthmic spondylolisthesis were at the L4–L5 (88.5%) and L5–S1 (84.6%) levels, respectively. Surgery in both groups significantly improved VAS and ODI scores. The efficacy of surgery based on subjective satisfaction rate and pain and disability improvement was similar in the degenerative and isthmic groups. Notable complications were also comparable in both groups. Conclusions: Neural decompression and posterolateral instrumented fusion significantly improved pain and disability in patients with degenerative and isthmic spondylolisthesis. The efficacy of surgery for overall subjective satisfaction rate and pain and disability improvement was similar in both groups.

A Survey on the Short-term Outcome of Microlumbar Discectomy with General versus Spinal Anesthesia

Mohsen Dashtbani,Mehrdad Mokaram Dori,Mohammad Hassani,Farzad Omidi-Kashani 대한정형외과학회 2019 Clinics in Orthopedic Surgery Vol.11 No.4

Background: Surgery on the lower thoracic and lumbosacral spine is possible with both general and spinal anesthesia, but most spine surgeons are reluctant to perform the surgery with spinal anesthesia. We aimed to conduct a survey on the short-term outcome of microlumbar discectomy in the patients who had been treated under general or spinal anesthesia. Methods: In this prospective study, we performed a survey on 72 patients who underwent microlumbar discectomy under general anesthesia (group A) or spinal anesthesia (group B). Demographic characteristics, American Society of Anesthesiologists physical status, duration of operation, blood loss, and complications were all documented. Preoperative and early postoperative (at the time of discharge) disability and pain were assessed by using Japanese Orthopedic Association (JOA) scoring system and a visual analog scale questionnaire. Results: The two groups were homogenous preoperatively. The mean intraoperative blood loss was less and the mean operating time was shorter in group A than in group B, but there was no statistically significant difference between groups. The rate of postoperative improvement in JOA score and improvement in pain were similar between groups. Anesthetic complications were unremarkable. Conclusions: Simple lumbar disc operations in the otherwise healthy patients can be safely performed under either spinal or general anesthesia. Both anesthetic methods led to comparable outcomes with minimal complications.

Effect of aortic spiral blood flow on wall shear stress in stenosed left main coronary arteries with varying take-off angle, stenosis severity and eccentricity

Abouzar Moshfegh,Ashkan Javadzadegan,Zhaoqi Zhang,Hamid Hassanzadeh Afrouzi,Mohammad Omidi 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.8

It is well accepted that blood flow in the human aorta is spiral by nature, with beneficial impacts for the cardiovascular system in the form of improved haemodynamics and efficient perfusion. This study investigates the effect of aortic spiral blood flow on wall shear stress (WSS) in computer-generated models of the left main trunk (LMT), also known as left main coronary artery, with varying take-off angle, stenosis severity and eccentricity. The results show that the spirality effect causes a substantial reduction in maximum WSS (WSS max ), average WSS (WSS ave ) and size of regions with low WSS. The effects of spiral flow on WSS max become more significant with increasing LMT take-off angle and stenosis eccentricity, and they become less significant with increasing stenosis severity. The aortic spiral blood flow intensity, LMT take-off angle, stenosis severity and eccentricity statistically significantly predict the WSS; however, the strongest predictor of WSS is stenosis severity (F(4, 399) = 3653.85, p < 0.001 for WSS max and F(4, 399) = 913.46, p < 0.001 for WSS ave ), followed by LMT take-off angle (F(4, 399) = 582.735, p < 0.001 for WSS max and F(4, 399) = 163.16, p < 0.001 for WSS ave ), stenosis eccentricity (F(4, 399) = 230.15, p < 0.001 for WSS max and F(4, 399) = 52.94, p < 0.001 for WSS ave ) and blood flow spirality (F(4, 399) = 112.37, p < 0.001 for WSS max and F(4, 399) = 32.18, p < 0.001 for WSS ave ). Our findings suggest that naturally or artificially induced spiral flow in the aorta potentially has atheroprotective effects in the LMT.